| 摘要 |
PROBLEM TO BE SOLVED: To provide an efficient method for producing a copolymerized polyester having less reduction in molecular weight on melting molding and thermal resistance and hydrolysis resistance requested for a molded article.SOLUTION: A method for producing a copolymerized aromatic polyester in which bis[4-(2-hydroxyethoxy)phenyl]sulfone is copolymerized by 55 mol% or more of all diol components and which has inherent viscosity of 0.50 to 0.65 dL/g includes at least following steps of: a transesterification of an aromatic dicarboxylic acid or derivatives thereof, an aliphatic diol and bis[4-(2-hydroxyethoxy)phenyl]sulfone under pressure of 0.05 MPa or more by using a transesterification catalyst (step 1); and polycondensation of a reactant manufactured in the step 1 by using a phosphorus compound and a germanium compound. |
